Model Definition

D661 = Series (integrated electronics, 24 VDC, NG10)

5625C = Spool/sleeve assembly; rated flow 60 L/min @ ΔP=35 bar (high‑linearity trim, standard response)

Typical full config example: G060KOAA5VSB0‑P

G060 = 60 L/min rated flow & standard response

KOAA = High‑linearity hydraulic layout, 24 VDC, ±10 V/±10 mA command, centered null

5 = 5+PE connector, IP65

VSB0 = FKM seals, extended temp range, LVDT 4–20 mA feedback

P = High‑linearity ServoJet® pilot stage

Technical Specifications

Hydraulic Parameters

Rated flow: 60 L/min (ΔP=35 bar)

Max working pressure: 350 bar (P/A/B); 210 bar (internal drain T) / 350 bar (external drain T)

Step response: 10–13 ms (0→100%, 210 bar)

Hysteresis: <0.08%

Resolution: <0.04%

Null drift: <1.0% (ΔT=55 K)

Null leakage: <12 mL/min

Fluid cleanliness: NAS 1638 Class 6 / ISO 4406 18/15

Electrical Parameters

Power supply: 24 VDC (18–32 VDC)

Control signal: ±10 V (differential) or ±10 mA

Feedback signal: 4–20 mA (LVDT spool position)

Connector: 5+PE, IP65

Current draw: ≤700 mA

Physical & Environmental

Operating temperature: −40 ℃ to +85 ℃

Weight: approx. 5.7 kg

Interface & Communication Configuration

Hydraulic interface: P/A/B/T, ISO 4401‑05 (NG10)

Electrical interface:

Power: 24 VDC, GND, PE

Command: ±10 V / ±10 mA

Feedback: 4–20 mA (spool position)

Status: Fault alarm output

Core Functions

High‑Linearity ServoJet® Pilot: Optimized for 60 L/min, minimal hysteresis, superior linearity

Integrated Precision PID Amplifier: Onboard dead‑zone compensation, thermal/overload protection, stable null

LVDT Closed‑Loop Feedback: Excellent resolution and repeatability for critical motion control

Fail‑Safe Centering: Spool returns to neutral on power loss

60 L/min High‑Linearity Flow: Tuned for medium‑sized hydraulic systems requiring ultra‑precision

Application Scenarios

Industrial automation: Ultra‑precision CNC machine tools, high‑accuracy hydraulic presses, medical molding machines

Test equipment: High‑precision structural fatigue testers, vibration simulation tables, aerospace actuator test benches

Metallurgy: Precision tension control, high‑accuracy AGC roll gap control in light mills

Energy: Wind turbine pitch control (high‑precision units), marine precision auxiliary hydraulic systems

Usage & Maintenance

Installation: Horizontal/vertical mounting; avoid severe vibration/shock

Fluid: ISO VG46 mineral oil; maintain cleanliness per NAS 1638 Class 6

Commissioning: Apply 24 VDC; connect ±10 V/±10 mA command; calibrate zero/gain via 4–20 mA feedback

Maintenance: Check fluid contamination every 3 months; calibrate zero/gain every 6 months; avoid long idle periods at high pressure